Balloon-Targeted Extra-Anatomic Sharp Recanalization Technique to Re-establish Supraclavicular Vascular Access

A balloon-targeted extra-anatomic sharp recanalization (BEST) technique was investigated to re-establish supraclavicular vascular access in patients with central venous occlusion. Query of the authors' institution's database yielded 130 patients who underwent central venous recanalization. Of these, a retrospective review of 5 patients with concurrent thoracic central venous and bilateral internal jugular vein occlusions who underwent sharp recanalization using the BEST technique from May 2018 to August 2022 was performed. Technical success was achieved in all cases without major adverse events. Four (80%) of the 5 patients underwent hemodialysis reliable outflow (HeRO) graft placement using the newly established supraclavicular vascular access.

Prospective Study of Radial Artery Occlusion Following Transradial Arterial Access during IR Procedures

PURPOSE

To prospectively determine the rate of radial artery occlusion (RAO) in patients undergoing transradial access for intra-arterial interventions.

MATERIALS AND METHODS

Seventy-seven patients undergoing transradial access from August 2019 to March 2021 for 120 intra-arterial procedures (yttrium-90 mapping [n = 39] and radioembolization [n = 38], uterine artery embolization [n = 19], transarterial chemoembolization [n = 10], active bleed embolization [n = 8], angiomyolipoma embolization [n = 4], and other [n = 2]) were enrolled. The average patient age was 59 years ± 13.1 (range, 30-90 years), and 43 (55.8%) of the 77 patients were men. The patients underwent radial artery (RA) palpation, ultrasound evaluation, the Barbeau test, and the reverse Barbeau test prior to and following the intervention. Verapamil, nitroglycerin, and heparin were administered in a total of 114 (95%) of the 120 procedures prior to starting the procedure. The incidence of RAO and radial artery spasm (RAS) was calculated, and univariate logistic regression was performed to analyze the predictors of RAS.

RESULTS

The preprocedural RA diameter (3.0 mm ± 0.67) was not significantly different from the postprocedural RA diameter (3.0 mm ± 0.65, P = .904). The RAO rate was determined to be 0.8% (1/120), and this artery recanalized within 1 week. Due to the small number of occlusions, statistical analysis of predictors of RAO was not performed. The rate of RAS was 22.7% (27/119). None of the variables tested-including age, sex, RA diameter, initial versus repeat access, operator experience, and artery puncture technique-showed significant prediction for RAS. Patients were seen for follow-up after 111 (92.5%) of the 120 procedures.

CONCLUSIONS

Transradial access resulted in a <1% rate of RAO.

Principles of Radioembolization

Radioembolization has become a mainstay therapy in the treatment of primary and secondary liver cancers. This article will specifically discuss a brief history of yttrium treatment as well as an overview of the physical properties of the currently available devices. A discussion of the mechanism of action will be followed by a discussion on patient selection for this treatment.

Principles of Radioembolization

Radioembolization has become a mainstay therapy in the treatment of primary and secondary liver cancers. This article will specifically discuss a brief history of yttrium treatment as well as an overview of the physical properties of the currently available devices. A discussion of the mechanism of action will be followed by a discussion on patient selection for this treatment.

Effect of intra-arterial vasodilator administration during radial artery access on systemic blood pressure in patients receiving moderate sedation

PURPOSE

The hemodynamic effects of intra-arterial vasodilator administration for the prevention of radial artery spasm during transradial access have not been well characterized. This study evaluates the effect of intra-arterial Verapamil and Nitroglycerine administration on systemic blood pressure and its correlation with timing of moderate sedation administration.

MATERIALS AND METHODS

Institutional review board approval was granted. Patients who underwent transradial access from 4/2018 to 4/2019 and received both intra-arterial vasodilators and moderate sedation were identified and their electronic medical records reviewed. Patients were divided into three cohorts based on the timing of sedation and intra-arterial vasodilator administration. Decrease in systolic blood pressure (SBP) was expressed as means with standard deviation which were then compared using Student's t-test.

RESULTS

A total of 84 patients who met inclusion criteria demonstrated an overall mean decrease in SBP of 16.45 mmHg ± 15.45 mmHg. Patients receiving sedation and intra-arterial vasodilators within their expected peak SBP effect times had similar SBP change following the intra-arterial vasodilators as those in whom the interval was greater than 10 min (4.2 mmHg; 95% CI (-4.11 to 12.52), p = 0.3171). Two patients experienced asymptomatic hypotension.

CONCLUSIONS

Patients undergoing transradial access for procedures utilizing moderate sedation can safely receive intra-arterial Verapamil and Nitroglycerine for prevention of radial artery spasm.

Treatment Options for Early-Stage Hepatocellular Carcinoma

Patients with early stage hepatocellular carcinoma have good prognosis and are treated with curative intent. Although this cohort of patients is generally defined by limited tumor burden, good liver function, and preserved functional status, there remains utility in further stratification to optimize overall survival and limit post-operative morbidity and mortality. Transplant, resection, ablation, transarterial radioembolization, and transarterial chemoembolization, either as monotherapy or in combination, may play a crucial role in treating this cohort of patients depending on a multitude of factors. In this section, we review each treatment modality and provide general guidelines for patient selection.

Outcomes of radioembolization for unresectable hepatocellular carcinoma in patients with marginal functional hepatic reserve

PURPOSE

To evaluate the outcomes of radioembolization (RE) as a therapy for unresectable hepatocellular carcinoma (HCC) in patients with marginal functional hepatic reserve.

METHODS

A retrospective review of 471 patients (1/2010-7/2015) treated with RE (Therasphere, BTG, UK) was performed. A total of 36 patients (mean age: 66.1±9.3, male: 86.1%) underwent therapy for HCC with a MELD≥15 (median: 16, range: 15-22). Baseline demographics of the study cohort were as follows: etiology (HCV: 26, 72.2%), cirrhosis (n=32, 88.9%), ECOG 0 (n=16, 44.4%), Child-Pugh class (A=15, B=19, C=2), unilobar distribution (n=27, 75%), AFP>200 (n=11, 30.6%), portal vein thrombosis (PVT, n=7, 19.4%), metastasis (n=3, 8.3%). Outcomes analyzed included CTCAEv4.03 laboratory toxicities (120-day), imaging response (mRECIST), progression-free survival (PFS), and overall survival (OS).

RESULTS

A total of 42 treatments were performed with mean dose of 2.02±1.23GBq. The cumulative grade 3/4 toxicity was 28% overall and 21% for bilirubin at 120-days. The objective response and disease control rates were 48.3% (14/29) and 69% (20/29) respectively. The median (95% CI) PFS was 5.9 (4.4-7.7) months. Ten (27.8%) patients received additional locoregional therapy at a median (IQR) of 138 (102-243) days post RE. The mean (95% CI) OS was 21.9 (14.8-29.0) months. The absence of PVT was associated with improved OS (p=0.005) Disease control at 90-days was also associated with an OS benefit (p=0.037).

CONCLUSIONS

Patients with unresectable HCC and marginal functional hepatic reserve treated with RE had favorable objective response and disease control rates, both predictive of overall survival.

Yttrium-90 Glass-Based Microsphere Radioembolization in the Treatment of Hepatocellular Carcinoma Secondary to the Hepatitis B Virus: Safety, Efficacy, and Survival

PURPOSE

To evaluate outcomes of yttrium-90 radioembolization performed with glass-based microspheres in the treatment of hepatocellular carcinoma (HCC) secondary to the hepatitis B virus (HBV).

MATERIALS AND METHODS

A total of 675 patients treated between January 2006 and July 2014 were reviewed, of which 45 (age 62 y ± 10; 91% male) received glass-based radioembolization for HCC secondary to HBV. All patients were stratified according to previous therapy (naive, n = 14; 31.1%), Child-Pugh class (class A, n = 41; 91%), Eastern Cooperative Oncology Group (ECOG) performance status (PS; < 1, n = 21; 47%), solitary (n = 26; 58%) and unilobar (n = 37; 82%) tumor distribution, tumor size < 5 cm (n = 29; 64%), portal vein thrombosis (n = 14; 31%), α-fetoprotein level > 400 ng/mL (n = 17; 38%), and Barcelona Clinic Liver Cancer stage (A, n = 8; B, n = 9; C, n = 28).

RESULTS

A total of 50 radioembolization treatments were performed, with a 100% technical success rate (median target dose, 120 Gy). Clinical toxicities included pain (16%), fatigue (12%), and nausea (4%). Grade 3/4 laboratory toxicities included bilirubin (8%) and aspartate aminotransferase (4%) toxicities. Observed toxicities were independent of treatment dose. The objective response rates were 55% per modified Response Evaluation Criteria In Solid Tumors and 21% per World Health Organization criteria, and the disease control rate was 63%. Disease progression was secondary to new, nontarget HCC in 45% of cases. Median time to progression and overall survival were 6.0 mo (95% confidence interval [CI], 4.4-8.0 mo) and 19.3 mo (95% CI, 11.2-22.7 mo), respectively. Multivariate analysis demonstrated ECOG PS ≥ 1 and AFP level > 400 ng/mL to be independent predictors of inferior overall survival.

CONCLUSIONS

Glass-based radioembolization for HCC secondary to HBV can be safely performed, with favorable target lesion response and overall survival.

Early postnatal exposure to methylphenidate alters stress reactivity and increases hippocampal ectopic granule cells in adult rats

To mimic clinical treatment with methylphenidate (MPH; Ritalin) for attention deficit/hyperactivity disorder (ADHD), rat pups were injected with MPH (5 mg/kg, i.p.) or placebo twice daily during their nocturnal active phase from postnatal day (PND) 7-35. Thirty-nine days after the last MPH administration (PND 76), four litters of rats experienced stressful conditions during the 2003 New York City blackout. MPH-treated rats that endured the blackout lost more weight and regained it at a slower pace than controls (p<0.05; N=7-11 per group). Furthermore, MPH-treated rats had elevated systolic arterial blood pressure (from 115.6+/-1.2 to 126+/-1.8 mmHg; p<0.05), assessed on PND 130 by tail cuff plethysmography. Immunocytochemical studies of transmitter systems in the brain demonstrated rearrangements of catecholamine and neuropeptide Y fibers in select brain regions at PND 135, which did not differ between blackout and control groups. However, MPH-treated rats that endured the blackout had more ectopic granule cells in the hilus of the dorsal hippocampal dentate gyrus compared to controls at PND 135 (p<0.05; N=6 per group). These findings indicate that early postnatal exposure to high therapeutic doses of MPH can have long lasting effects on the plasticity of select brain regions and can induce changes in the reactivity to stress that persist into adulthood.

Estrogen and aging affect synaptic distribution of phosphorylated LIM kinase (pLIMK) in CA1 region of female rat hippocampus

17beta-Estradiol (E) increases axospinous synapse density in the hippocampal CA1 region of young female rats, but not in aged rats. This may be linked to age-related alterations in signaling pathways activated by synaptic estrogen receptor alpha (ER-alpha) that potentially regulate spine formation, such as LIM-kinase (LIMK), an actin depolymerizing factor/cofilin kinase. We hypothesized that, as with ER-alpha, phospho-LIM-kinase (pLIMK) may be less abundant or responsive to E in CA1 synapses of aged female rats. To address this, cellular and subcellular distribution of pLIMK-immunoreactivity (IR) in CA1 was analyzed by light and electron microscopy in young and aged female rats that were ovariectomized and treated with either vehicle or E. pLIMK-IR was found primarily in perikarya within the pyramidal cell layer and dendritic shafts and spines in stratum radiatum (SR). While pLIMK-IR was occasionally present in terminals, post-embedding quantitative analysis of SR showed that pLIMK had a predominant post-synaptic localization and was preferentially localized within the postsynaptic density (PSD). The percentage of pLIMK-labeled synapses increased (30%) with E treatment (P<0.02) in young animals, and decreased (43%) with age (P<0.002) regardless of treatment. The pattern of distribution of pLIMK-IR within dendritic spines and synapses was unaffected by age or E treatment, with the exception of an E-induced increase in the non-synaptic core of spines in young females. These data suggest that age-related synaptic alterations similar to those seen with ER-alpha occur with signaling molecules such as pLIMK, and support the hypothesis that age-related failure of E treatment to increase synapse number in CA1 may be due to changes in the molecular profile of axospinous synapses with respect to signaling pathways linked to formation of additional spines and synapses in response to E.

Methylphenidate administration to juvenile rats alters brain areas involved in cognition, motivated behaviors, appetite, and stress

Thousands of children receive methylphenidate (MPH; Ritalin) for attention deficit/hyperactivity disorder (ADHD), yet the long-term neurochemical consequences of MPH treatment are unknown. To mimic clinical Ritalin treatment in children, male rats were injected with MPH (5 mg/kg) or vehicle twice daily from postnatal day 7 (PND7)-PND35. At the end of administration (PND35) or in adulthood (PND135), brain sections from littermate pairs were immunocytochemically labeled for neurotransmitters and cytological markers in 16 regions implicated in MPH effects and/or ADHD etiology. At PND35, the medial prefrontal cortex (mPFC) of rats given MPH showed 55% greater immunoreactivity (-ir) for the catecholamine marker tyrosine hydroxylase (TH), 60% more Nissl-stained cells, and 40% less norepinephrine transporter (NET)-ir density. In hippocampal dentate gyrus, MPH-receiving rats showed a 51% decrease in NET-ir density and a 61% expanded distribution of the new-cell marker PSA-NCAM (polysialylated form of neural cell adhesion molecule). In medial striatum, TH-ir decreased by 21%, and in hypothalamus neuropeptide Y-ir increased by 10% in MPH-exposed rats. At PND135, MPH-exposed rats exhibited decreased anxiety in the elevated plus-maze and a trend for decreased TH-ir in the mPFC. Neither PND35 nor PND135 rats showed major structural differences with MPH exposure. These findings suggest that developmental exposure to high therapeutic doses of MPH has short-term effects on select neurotransmitters in brain regions involved in motivated behaviors, cognition, appetite, and stress. Although the observed neuroanatomical changes largely resolve with time, chronic modulation of young brains with MPH may exert effects on brain neurochemistry that modify some behaviors even in adulthood.

Ultrastructural localization of estrogen receptor beta immunoreactivity in the rat hippocampal formation

Several lines of evidence indicate that estrogen affects hippocampal synaptic plasticity through rapid nongenomic mechanisms, possibly by binding to plasma membrane estrogen receptors (ERs). We have previously shown that ERalpha immunoreactivity (ir) is in select interneuron nuclei and in several extranuclear locations, including dendritic spines and axon terminals, within the rat hippocampal formation (Milner et al., [2001] J Comp Neurol 429:355). The present study sought to determine the cellular and subcellular locations of ERbeta-ir. Coronal hippocampal sections from diestrus rats were immunolabeled with antibodies to ERbeta and examined by light and electron microscopy. By light microscopy, ERbeta-ir was primarily in the perikarya and proximal dendrites of pyramidal and granule cells. ERbeta-ir was also in a few nonprincipal cells and scattered nuclei in the ventral subiculum and CA3 region. Ultrastructural analysis revealed ERbeta-ir at several extranuclear sites in all hippocampal subregions. ERbeta-ir was affiliated with cytoplasmic organelles, especially endomembranes and mitochondria, and with plasma membranes primarily of principal cell perikarya and proximal dendrites. ERbeta-ir was in dendritic spines, many arising from pyramidal and granule cell dendrites. In both dendritic shafts and spines, ERbeta-ir was near the perisynaptic zone adjacent to synapses formed by unlabeled terminals. ERbeta-ir was in preterminal axons and axon terminals, associated with clusters of small, synaptic vesicles. ERbeta-labeled terminals formed both asymmetric and symmetric synapses with dendrites. ERbeta-ir also was detected in glial profiles. The cellular and subcellular localization of ERbeta-ir was generally similar to that of ERalpha, except that ERbeta was more extensively found at extranuclear sites. These results suggest that ERbeta may serve primarily as a nongenomic transducer of estrogen actions in the hippocampal formation.

Ultrastructural evidence that androgen receptors are located at extranuclear sites in the rat hippocampal formation

Like estrogens in female rats, androgens can affect dendritic spine density in the CA1 subfield of the male rat hippocampus [J Neurosci 23:1588 (2003)]. Previous light microscopic studies have shown that androgen receptors (ARs) are present in the nuclei of CA1 pyramidal cells. However, androgens may also exert their effects through rapid non-genomic mechanisms, possibly by binding to membranes. Thus, to investigate whether ARs are at potential extranuclear sites of ARs, antibodies to ARs were localized by light and electron microscopy in the male rat hippocampal formation. By light microscopy, AR immunoreactivity (-ir) was found in CA1 pyramidal cell nuclei and in disperse, punctate processes that were most dense in the pyramidal cell layer. Additionally, diffuse AR-ir was found in the mossy fiber pathway. Ultrastructural analysis revealed AR-ir at several extranuclear sites in all hippocampal subregions. AR-ir was found in dendritic spines, many arising from pyramidal and granule cell dendrites. AR-ir was associated with clusters of small, synaptic vesicles within preterminal axons and axon terminals. Labeled preterminal axons were most prominent in stratum lucidum of the CA3 region. AR-containing terminals formed asymmetric synapses or did not form synaptic junctions in the plane of section analyzed. AR-ir also was detected in astrocytic profiles, many of which apposed terminals synapsing on unlabeled dendritic spines or formed gap junctions with other AR-labeled or unlabeled astrocytes. Collectively, these results suggest that ARs may serve as both a genomic and non-genomic transducer of androgen action in the hippocampal formation.

Ultrastructural evidence for mu-opioid modulation of cholinergic pathways in rat dentate gyrus

Within the rat hippocampal formation, cholinergic afferents and mu-opioid receptors (MORs) are involved in many crucial learning processes, including those associated with drug reward. Pharmacological data, and the overlapping distributions of cholinergic and mu-opioid systems, particularly in the dentate gyrus, suggest that MOR activation is a potential mechanism for endogenous opioid modulation of cholinergic activity. To date, anatomical evidence supporting this has not been reported. To delineate the relationship between cholinergic afferents and MOR-containing processes in the dentate gyrus, hippocampal sections were dually immunolabeled for vesicular acetylcholine transporter (VAChT) and MOR-1 and examined by electron microscopy. VAChT immunoreactivity was in unmyelinated axons and axon terminals, and was most often associated with small synaptic vesicles. MOR immunoreactivity was found in axons, axon terminals and, to a lesser extent, perikarya, which resembled GABAergic basket cells. Semi-quantitative ultrastructural analysis revealed that from 5% to 13% (depending on laminar location) of VAChT-immunoreactive (ir) presynaptic profiles contained MOR immunoreactivity. Additionally, 7% of VAChT-ir presynaptic profiles directly apposed MOR-ir axons and terminals, and there were almost no appositions to MOR-ir dendrites. These data suggest that opioids may directly and indirectly modulate acetylcholine release and/or reuptake. In the hilus and molecular layer, 4% of VAChT-ir terminals contacted dendritic shafts that were also contacted by MOR-ir terminals. This suggests that cholinergic afferents and MOR-containing afferents can converge on granule cell dendrites (which are restricted to the molecular layer) and on interneuron dendrites in the hilus. The results of this study provide ultrastructural evidence for direct and indirect modulation of cholinergic systems by mu-opioids in the hippocampal formation.